drivers/scsi/sg.c

   1 /*
   2  *  History:
   3  *  Started: Aug 9 by Lawrence Foard (entropy@world.std.com),
   4  *           to allow user process control of SCSI devices.
   5  *  Development Sponsored by Killy Corp. NY NY
   6  *
   7  * Original driver (sg.c):
   8  *        Copyright (C) 1992 Lawrence Foard
   9  * Version 2 and 3 extensions to driver:
  10  *        Copyright (C) 1998 - 2014 Douglas Gilbert
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2, or (at your option)
  15  * any later version.
  16  *
  17  */
  18
  19 static int sg_version_num = 30536;      /* 2 digits for each component */
  20 #define SG_VERSION_STR "3.5.36"
  21
  22 /*
  23  *  D. P. Gilbert (dgilbert@interlog.com), notes:
  24  *      - scsi logging is available via SCSI_LOG_TIMEOUT macros. First
  25  *        the kernel/module needs to be built with CONFIG_SCSI_LOGGING
  26  *        (otherwise the macros compile to empty statements).
  27  *
  28  */
  29 #include <linux/module.h>
  30
  31 #include <linux/fs.h>
  32 #include <linux/kernel.h>
  33 #include <linux/sched.h>
  34 #include <linux/string.h>
  35 #include <linux/mm.h>
  36 #include <linux/errno.h>
  37 #include <linux/mtio.h>
  38 #include <linux/ioctl.h>
  39 #include <linux/slab.h>
  40 #include <linux/fcntl.h>
  41 #include <linux/init.h>
  42 #include <linux/poll.h>
  43 #include <linux/moduleparam.h>
  44 #include <linux/cdev.h>
  45 #include <linux/idr.h>
  46 #include <linux/seq_file.h>
  47 #include <linux/blkdev.h>
  48 #include <linux/delay.h>
  49 #include <linux/blktrace_api.h>
  50 #include <linux/mutex.h>
  51 #include <linux/atomic.h>
  52 #include <linux/ratelimit.h>
  53 #include <linux/uio.h>
  54 #include <linux/cred.h> /* for sg_check_file_access() */
  55
  56 #include "scsi.h"
  57 #include <scsi/scsi_dbg.h>
  58 #include <scsi/scsi_host.h>
  59 #include <scsi/scsi_driver.h>
  60 #include <scsi/scsi_ioctl.h>
  61 #include <scsi/sg.h>
  62
  63 #include "scsi_logging.h"
  64
  65 #ifdef CONFIG_SCSI_PROC_FS
  66 #include <linux/proc_fs.h>
  67 static char *sg_version_date = "20140603";
  68
  69 static int sg_proc_init(void);
  70 #endif
  71
  72 #define SG_ALLOW_DIO_DEF 0
  73
  74 #define SG_MAX_DEVS 32768
  75
  76 /* SG_MAX_CDB_SIZE should be 260 (spc4r37 section 3.1.30) however the type
  77  * of sg_io_hdr::cmd_len can only represent 255. All SCSI commands greater
  78  * than 16 bytes are "variable length" whose length is a multiple of 4
  79  */
  80 #define SG_MAX_CDB_SIZE 252
  81
  82 #define SG_DEFAULT_TIMEOUT mult_frac(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
  83
  84 int sg_big_buff = SG_DEF_RESERVED_SIZE;
  85 /* N.B. This variable is readable and writeable via
  86    /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
  87    of this size (or less if there is not enough memory) will be reserved
  88    for use by this file descriptor. [Deprecated usage: this variable is also
  89    readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
  90    the kernel (i.e. it is not a module).] */
  91 static int def_reserved_size = -1;      /* picks up init parameter */
  92 static int sg_allow_dio = SG_ALLOW_DIO_DEF;
  93
  94 static int scatter_elem_sz = SG_SCATTER_SZ;
  95 static int scatter_elem_sz_prev = SG_SCATTER_SZ;
  96
  97 #define SG_SECTOR_SZ 512
  98
  99 static int sg_add_device(struct device *, struct class_interface *);
 100 static void sg_remove_device(struct device *, struct class_interface *);
 101
 102 static DEFINE_IDR(sg_index_idr);
 103 static DEFINE_RWLOCK(sg_index_lock);    /* Also used to lock
 104                                                            file descriptor list for device */
 105
 106 static struct class_interface sg_interface = {
 107         .add_dev        = sg_add_device,
 108         .remove_dev     = sg_remove_device,
 109 };
 110
 111 typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
 112         unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
 113         unsigned sglist_len; /* size of malloc'd scatter-gather list ++ */
 114         unsigned bufflen;       /* Size of (aggregate) data buffer */
 115         struct page **pages;
 116         int page_order;
 117         char dio_in_use;        /* 0->indirect IO (or mmap), 1->dio */
 118         unsigned char cmd_opcode; /* first byte of command */
 119 } Sg_scatter_hold;
 120
 121 struct sg_device;               /* forward declarations */
 122 struct sg_fd;
 123
 124 typedef struct sg_request {     /* SG_MAX_QUEUE requests outstanding per file */
 125         struct list_head entry; /* list entry */
 126         struct sg_fd *parentfp; /* NULL -> not in use */
 127         Sg_scatter_hold data;   /* hold buffer, perhaps scatter list */
 128         sg_io_hdr_t header;     /* scsi command+info, see <scsi/sg.h> */
 129         unsigned char sense_b[SCSI_SENSE_BUFFERSIZE];
 130         char res_used;          /* 1 -> using reserve buffer, 0 -> not ... */
 131         char orphan;            /* 1 -> drop on sight, 0 -> normal */
 132         char sg_io_owned;       /* 1 -> packet belongs to SG_IO */
 133         /* done protected by rq_list_lock */
 134         char done;              /* 0->before bh, 1->before read, 2->read */
 135         struct request *rq;
 136         struct bio *bio;
 137         struct execute_work ew;
 138 } Sg_request;
 139
 140 typedef struct sg_fd {          /* holds the state of a file descriptor */
 141         struct list_head sfd_siblings;  /* protected by device's sfd_lock */
 142         struct sg_device *parentdp;     /* owning device */
 143         wait_queue_head_t read_wait;    /* queue read until command done */
 144         rwlock_t rq_list_lock;  /* protect access to list in req_arr */
 145         struct mutex f_mutex;   /* protect against changes in this fd */
 146         int timeout;            /* defaults to SG_DEFAULT_TIMEOUT      */
 147         int timeout_user;       /* defaults to SG_DEFAULT_TIMEOUT_USER */
 148         Sg_scatter_hold reserve;        /* buffer held for this file descriptor */
 149         struct list_head rq_list; /* head of request list */
 150         struct fasync_struct *async_qp; /* used by asynchronous notification */
 151         Sg_request req_arr[SG_MAX_QUEUE];       /* used as singly-linked list */
 152         char force_packid;      /* 1 -> pack_id input to read(), 0 -> ignored */
 153         char cmd_q;             /* 1 -> allow command queuing, 0 -> don't */
 154         unsigned char next_cmd_len; /* 0: automatic, >0: use on next write() */
 155         char keep_orphan;       /* 0 -> drop orphan (def), 1 -> keep for read() */
 156         char mmap_called;       /* 0 -> mmap() never called on this fd */
 157         char res_in_use;        /* 1 -> 'reserve' array in use */
 158         struct kref f_ref;
 159         struct execute_work ew;
 160 } Sg_fd;
 161
 162 typedef struct sg_device { /* holds the state of each scsi generic device */
 163         struct scsi_device *device;
 164         wait_queue_head_t open_wait;    /* queue open() when O_EXCL present */
 165         struct mutex open_rel_lock;     /* held when in open() or release() */
 166         int sg_tablesize;       /* adapter's max scatter-gather table size */
 167         u32 index;              /* device index number */
 168         struct list_head sfds;
 169         rwlock_t sfd_lock;      /* protect access to sfd list */
 170         atomic_t detaching;     /* 0->device usable, 1->device detaching */
 171         bool exclude;           /* 1->open(O_EXCL) succeeded and is active */
 172         int open_cnt;           /* count of opens (perhaps < num(sfds) ) */
 173         char sgdebug;           /* 0->off, 1->sense, 9->dump dev, 10-> all devs */
 174         struct gendisk *disk;
 175         struct cdev * cdev;     /* char_dev [sysfs: /sys/cdev/major/sg<n>] */
 176         struct kref d_ref;
 177 } Sg_device;
 178
 179 /* tasklet or soft irq callback */
 180 static void sg_rq_end_io(struct request *rq, blk_status_t status);
 181 static int sg_start_req(Sg_request *srp, unsigned char *cmd);
 182 static int sg_finish_rem_req(Sg_request * srp);
 183 static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
 184 static ssize_t sg_new_read(Sg_fd * sfp, char __user *buf, size_t count,
 185                            Sg_request * srp);
 186 static ssize_t sg_new_write(Sg_fd *sfp, struct file *file,
 187                         const char __user *buf, size_t count, int blocking,
 188                         int read_only, int sg_io_owned, Sg_request **o_srp);
 189 static int sg_common_write(Sg_fd * sfp, Sg_request * srp,
 190                            unsigned char *cmnd, int timeout, int blocking);
 191 static int sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer);
 192 static void sg_remove_scat(Sg_fd * sfp, Sg_scatter_hold * schp);
 193 static void sg_build_reserve(Sg_fd * sfp, int req_size);
 194 static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
 195 static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
 196 static Sg_fd *sg_add_sfp(Sg_device * sdp);
 197 static void sg_remove_sfp(struct kref *);
 198 static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id, bool *busy);
 199 static Sg_request *sg_add_request(Sg_fd * sfp);
 200 static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
 201 static Sg_device *sg_get_dev(int dev);
 202 static void sg_device_destroy(struct kref *kref);
 203
 204 #define SZ_SG_HEADER sizeof(struct sg_header)
 205 #define SZ_SG_IO_HDR sizeof(sg_io_hdr_t)
 206 #define SZ_SG_IOVEC sizeof(sg_iovec_t)
 207 #define SZ_SG_REQ_INFO sizeof(sg_req_info_t)
 208
 209 #define sg_printk(prefix, sdp, fmt, a...) \
 210         sdev_prefix_printk(prefix, (sdp)->device,               \
 211                            (sdp)->disk->disk_name, fmt, ##a)
 212
 213 /*
 214  * The SCSI interfaces that use read() and write() as an asynchronous variant of
 215  * ioctl(..., SG_IO, ...) are fundamentally unsafe, since there are lots of ways
 216  * to trigger read() and write() calls from various contexts with elevated
 217  * privileges. This can lead to kernel memory corruption (e.g. if these
 218  * interfaces are called through splice()) and privilege escalation inside
 219  * userspace (e.g. if a process with access to such a device passes a file
 220  * descriptor to a SUID binary as stdin/stdout/stderr).
 221  *
 222  * This function provides protection for the legacy API by restricting the
 223  * calling context.
 224  */
 225 static int sg_check_file_access(struct file *filp, const char *caller)
 226 {
 227         if (filp->f_cred != current_real_cred()) {
 228                 pr_err_once("%s: process %d (%s) changed security contexts after opening file descriptor, this is not allowed.\n",
 229                         caller, task_tgid_vnr(current), current->comm);
 230                 return -EPERM;
 231         }
 232         if (uaccess_kernel()) {
 233                 pr_err_once("%s: process %d (%s) called from kernel context, this is not allowed.\n",
 234                         caller, task_tgid_vnr(current), current->comm);
 235                 return -EACCES;
 236         }
 237         return 0;
 238 }
 239
 240 static int sg_allow_access(struct file *filp, unsigned char *cmd)
 241 {
 242         struct sg_fd *sfp = filp->private_data;
 243
 244         if (sfp->parentdp->device->type == TYPE_SCANNER)
 245                 return 0;
 246
 247         return blk_verify_command(cmd, filp->f_mode);
 248 }
 249
 250 static int
 251 open_wait(Sg_device *sdp, int flags)
 252 {
 253         int retval = 0;
 254
 255         if (flags & O_EXCL) {
 256                 while (sdp->open_cnt > 0) {
 257                         mutex_unlock(&sdp->open_rel_lock);
 258                         retval = wait_event_interruptible(sdp->open_wait,
 259                                         (atomic_read(&sdp->detaching) ||
 260                                          !sdp->open_cnt));
 261                         mutex_lock(&sdp->open_rel_lock);
 262
 263                         if (retval) /* -ERESTARTSYS */
 264                                 return retval;
 265                         if (atomic_read(&sdp->detaching))
 266                                 return -ENODEV;
 267                 }
 268         } else {
 269                 while (sdp->exclude) {
 270                         mutex_unlock(&sdp->open_rel_lock);
 271                         retval = wait_event_interruptible(sdp->open_wait,
 272                                         (atomic_read(&sdp->detaching) ||
 273                                          !sdp->exclude));
 274                         mutex_lock(&sdp->open_rel_lock);
 275
 276                         if (retval) /* -ERESTARTSYS */
 277                                 return retval;
 278                         if (atomic_read(&sdp->detaching))
 279                                 return -ENODEV;
 280                 }
 281         }
 282
 283         return retval;
 284 }
 285
 286 /* Returns 0 on success, else a negated errno value */
 287 static int
 288 sg_open(struct inode *inode, struct file *filp)
 289 {
 290         int dev = iminor(inode);
 291         int flags = filp->f_flags;
 292         struct request_queue *q;
 293         Sg_device *sdp;
 294         Sg_fd *sfp;
 295         int retval;
 296
 297         nonseekable_open(inode, filp);
 298         if ((flags & O_EXCL) && (O_RDONLY == (flags & O_ACCMODE)))
 299                 return -EPERM; /* Can't lock it with read only access */
 300         sdp = sg_get_dev(dev);
 301         if (IS_ERR(sdp))
 302                 return PTR_ERR(sdp);
 303
 304         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 305                                       "sg_open: flags=0x%x\n", flags));
 306
 307         /* This driver's module count bumped by fops_get in <linux/fs.h> */
 308         /* Prevent the device driver from vanishing while we sleep */
 309         retval = scsi_device_get(sdp->device);
 310         if (retval)
 311                 goto sg_put;
 312
 313         retval = scsi_autopm_get_device(sdp->device);
 314         if (retval)
 315                 goto sdp_put;
 316
 317         /* scsi_block_when_processing_errors() may block so bypass
 318          * check if O_NONBLOCK. Permits SCSI commands to be issued
 319          * during error recovery. Tread carefully. */
 320         if (!((flags & O_NONBLOCK) ||
 321               scsi_block_when_processing_errors(sdp->device))) {
 322                 retval = -ENXIO;
 323                 /* we are in error recovery for this device */
 324                 goto error_out;
 325         }
 326
 327         mutex_lock(&sdp->open_rel_lock);
 328         if (flags & O_NONBLOCK) {
 329                 if (flags & O_EXCL) {
 330                         if (sdp->open_cnt > 0) {
 331                                 retval = -EBUSY;
 332                                 goto error_mutex_locked;
 333                         }
 334                 } else {
 335                         if (sdp->exclude) {
 336                                 retval = -EBUSY;
 337                                 goto error_mutex_locked;
 338                         }
 339                 }
 340         } else {
 341                 retval = open_wait(sdp, flags);
 342                 if (retval) /* -ERESTARTSYS or -ENODEV */
 343                         goto error_mutex_locked;
 344         }
 345
 346         /* N.B. at this point we are holding the open_rel_lock */
 347         if (flags & O_EXCL)
 348                 sdp->exclude = true;
 349
 350         if (sdp->open_cnt < 1) {  /* no existing opens */
 351                 sdp->sgdebug = 0;
 352                 q = sdp->device->request_queue;
 353                 sdp->sg_tablesize = queue_max_segments(q);
 354         }
 355         sfp = sg_add_sfp(sdp);
 356         if (IS_ERR(sfp)) {
 357                 retval = PTR_ERR(sfp);
 358                 goto out_undo;
 359         }
 360
 361         filp->private_data = sfp;
 362         sdp->open_cnt++;
 363         mutex_unlock(&sdp->open_rel_lock);
 364
 365         retval = 0;
 366 sg_put:
 367         kref_put(&sdp->d_ref, sg_device_destroy);
 368         return retval;
 369
 370 out_undo:
 371         if (flags & O_EXCL) {
 372                 sdp->exclude = false;   /* undo if error */
 373                 wake_up_interruptible(&sdp->open_wait);
 374         }
 375 error_mutex_locked:
 376         mutex_unlock(&sdp->open_rel_lock);
 377 error_out:
 378         scsi_autopm_put_device(sdp->device);
 379 sdp_put:
 380         scsi_device_put(sdp->device);
 381         goto sg_put;
 382 }
 383
 384 /* Release resources associated with a successful sg_open()
 385  * Returns 0 on success, else a negated errno value */
 386 static int
 387 sg_release(struct inode *inode, struct file *filp)
 388 {
 389         Sg_device *sdp;
 390         Sg_fd *sfp;
 391
 392         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 393                 return -ENXIO;
 394         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp, "sg_release\n"));
 395
 396         mutex_lock(&sdp->open_rel_lock);
 397         scsi_autopm_put_device(sdp->device);
 398         kref_put(&sfp->f_ref, sg_remove_sfp);
 399         sdp->open_cnt--;
 400
 401         /* possibly many open()s waiting on exlude clearing, start many;
 402          * only open(O_EXCL)s wait on 0==open_cnt so only start one */
 403         if (sdp->exclude) {
 404                 sdp->exclude = false;
 405                 wake_up_interruptible_all(&sdp->open_wait);
 406         } else if (0 == sdp->open_cnt) {
 407                 wake_up_interruptible(&sdp->open_wait);
 408         }
 409         mutex_unlock(&sdp->open_rel_lock);
 410         return 0;
 411 }
 412
 413 static ssize_t
 414 sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
 415 {
 416         Sg_device *sdp;
 417         Sg_fd *sfp;
 418         Sg_request *srp;
 419         int req_pack_id = -1;
 420         bool busy;
 421         sg_io_hdr_t *hp;
 422         struct sg_header *old_hdr = NULL;
 423         int retval = 0;
 424
 425         /*
 426          * This could cause a response to be stranded. Close the associated
 427          * file descriptor to free up any resources being held.
 428          */
 429         retval = sg_check_file_access(filp, __func__);
 430         if (retval)
 431                 return retval;
 432
 433         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 434                 return -ENXIO;
 435         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 436                                       "sg_read: count=%d\n", (int) count));
 437
 438         if (!access_ok(VERIFY_WRITE, buf, count))
 439                 return -EFAULT;
 440         if (sfp->force_packid && (count >= SZ_SG_HEADER)) {
 441                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
 442                 if (!old_hdr)
 443                         return -ENOMEM;
 444                 if (__copy_from_user(old_hdr, buf, SZ_SG_HEADER)) {
 445                         retval = -EFAULT;
 446                         goto free_old_hdr;
 447                 }
 448                 if (old_hdr->reply_len < 0) {
 449                         if (count >= SZ_SG_IO_HDR) {
 450                                 sg_io_hdr_t *new_hdr;
 451                                 new_hdr = kmalloc(SZ_SG_IO_HDR, GFP_KERNEL);
 452                                 if (!new_hdr) {
 453                                         retval = -ENOMEM;
 454                                         goto free_old_hdr;
 455                                 }
 456                                 retval =__copy_from_user
 457                                     (new_hdr, buf, SZ_SG_IO_HDR);
 458                                 req_pack_id = new_hdr->pack_id;
 459                                 kfree(new_hdr);
 460                                 if (retval) {
 461                                         retval = -EFAULT;
 462                                         goto free_old_hdr;
 463                                 }
 464                         }
 465                 } else
 466                         req_pack_id = old_hdr->pack_id;
 467         }
 468         srp = sg_get_rq_mark(sfp, req_pack_id, &busy);
 469         if (!srp) {             /* now wait on packet to arrive */
 470                 if (filp->f_flags & O_NONBLOCK) {
 471                         retval = -EAGAIN;
 472                         goto free_old_hdr;
 473                 }
 474                 retval = wait_event_interruptible(sfp->read_wait,
 475                         ((srp = sg_get_rq_mark(sfp, req_pack_id, &busy)) ||
 476                         (!busy && atomic_read(&sdp->detaching))));
 477                 if (!srp) {
 478                         /* signal or detaching */
 479                         if (!retval)
 480                                 retval = -ENODEV;
 481                         goto free_old_hdr;
 482                 }
 483         }
 484         if (srp->header.interface_id != '\0') {
 485                 retval = sg_new_read(sfp, buf, count, srp);
 486                 goto free_old_hdr;
 487         }
 488
 489         hp = &srp->header;
 490         if (old_hdr == NULL) {
 491                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
 492                 if (! old_hdr) {
 493                         retval = -ENOMEM;
 494                         goto free_old_hdr;
 495                 }
 496         }
 497         memset(old_hdr, 0, SZ_SG_HEADER);
 498         old_hdr->reply_len = (int) hp->timeout;
 499         old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
 500         old_hdr->pack_id = hp->pack_id;
 501         old_hdr->twelve_byte =
 502             ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
 503         old_hdr->target_status = hp->masked_status;
 504         old_hdr->host_status = hp->host_status;
 505         old_hdr->driver_status = hp->driver_status;
 506         if ((CHECK_CONDITION & hp->masked_status) ||
 507             (DRIVER_SENSE & hp->driver_status))
 508                 memcpy(old_hdr->sense_buffer, srp->sense_b,
 509                        sizeof (old_hdr->sense_buffer));
 510         switch (hp->host_status) {
 511         /* This setup of 'result' is for backward compatibility and is best
 512            ignored by the user who should use target, host + driver status */
 513         case DID_OK:
 514         case DID_PASSTHROUGH:
 515         case DID_SOFT_ERROR:
 516                 old_hdr->result = 0;
 517                 break;
 518         case DID_NO_CONNECT:
 519         case DID_BUS_BUSY:
 520         case DID_TIME_OUT:
 521                 old_hdr->result = EBUSY;
 522                 break;
 523         case DID_BAD_TARGET:
 524         case DID_ABORT:
 525         case DID_PARITY:
 526         case DID_RESET:
 527         case DID_BAD_INTR:
 528                 old_hdr->result = EIO;
 529                 break;
 530         case DID_ERROR:
 531                 old_hdr->result = (srp->sense_b[0] == 0 &&
 532                                   hp->masked_status == GOOD) ? 0 : EIO;
 533                 break;
 534         default:
 535                 old_hdr->result = EIO;
 536                 break;
 537         }
 538
 539         /* Now copy the result back to the user buffer.  */
 540         if (count >= SZ_SG_HEADER) {
 541                 if (__copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
 542                         retval = -EFAULT;
 543                         goto free_old_hdr;
 544                 }
 545                 buf += SZ_SG_HEADER;
 546                 if (count > old_hdr->reply_len)
 547                         count = old_hdr->reply_len;
 548                 if (count > SZ_SG_HEADER) {
 549                         if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
 550                                 retval = -EFAULT;
 551                                 goto free_old_hdr;
 552                         }
 553                 }
 554         } else
 555                 count = (old_hdr->result == 0) ? 0 : -EIO;
 556         sg_finish_rem_req(srp);
 557         sg_remove_request(sfp, srp);
 558         retval = count;
 559 free_old_hdr:
 560         kfree(old_hdr);
 561         return retval;
 562 }
 563
 564 static ssize_t
 565 sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
 566 {
 567         sg_io_hdr_t *hp = &srp->header;
 568         int err = 0, err2;
 569         int len;
 570
 571         if (count < SZ_SG_IO_HDR) {
 572                 err = -EINVAL;
 573                 goto err_out;
 574         }
 575         hp->sb_len_wr = 0;
 576         if ((hp->mx_sb_len > 0) && hp->sbp) {
 577                 if ((CHECK_CONDITION & hp->masked_status) ||
 578                     (DRIVER_SENSE & hp->driver_status)) {
 579                         int sb_len = SCSI_SENSE_BUFFERSIZE;
 580                         sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
 581                         len = 8 + (int) srp->sense_b[7];        /* Additional sense length field */
 582                         len = (len > sb_len) ? sb_len : len;
 583                         if (copy_to_user(hp->sbp, srp->sense_b, len)) {
 584                                 err = -EFAULT;
 585                                 goto err_out;
 586                         }
 587                         hp->sb_len_wr = len;
 588                 }
 589         }
 590         if (hp->masked_status || hp->host_status || hp->driver_status)
 591                 hp->info |= SG_INFO_CHECK;
 592         if (copy_to_user(buf, hp, SZ_SG_IO_HDR)) {
 593                 err = -EFAULT;
 594                 goto err_out;
 595         }
 596 err_out:
 597         err2 = sg_finish_rem_req(srp);
 598         sg_remove_request(sfp, srp);
 599         return err ? : err2 ? : count;
 600 }
 601
 602 static ssize_t
 603 sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
 604 {
 605         int mxsize, cmd_size, k;
 606         int input_size, blocking;
 607         unsigned char opcode;
 608         Sg_device *sdp;
 609         Sg_fd *sfp;
 610         Sg_request *srp;
 611         struct sg_header old_hdr;
 612         sg_io_hdr_t *hp;
 613         unsigned char cmnd[SG_MAX_CDB_SIZE];
 614         int retval;
 615
 616         retval = sg_check_file_access(filp, __func__);
 617         if (retval)
 618                 return retval;
 619
 620         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 621                 return -ENXIO;
 622         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 623                                       "sg_write: count=%d\n", (int) count));
 624         if (atomic_read(&sdp->detaching))
 625                 return -ENODEV;
 626         if (!((filp->f_flags & O_NONBLOCK) ||
 627               scsi_block_when_processing_errors(sdp->device)))
 628                 return -ENXIO;
 629
 630         if (!access_ok(VERIFY_READ, buf, count))
 631                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 632         if (count < SZ_SG_HEADER)
 633                 return -EIO;
 634         if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
 635                 return -EFAULT;
 636         blocking = !(filp->f_flags & O_NONBLOCK);
 637         if (old_hdr.reply_len < 0)
 638                 return sg_new_write(sfp, filp, buf, count,
 639                                     blocking, 0, 0, NULL);
 640         if (count < (SZ_SG_HEADER + 6))
 641                 return -EIO;    /* The minimum scsi command length is 6 bytes. */
 642
 643         if (!(srp = sg_add_request(sfp))) {
 644                 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sdp,
 645                                               "sg_write: queue full\n"));
 646                 return -EDOM;
 647         }
 648         buf += SZ_SG_HEADER;
 649         __get_user(opcode, buf);
 650         mutex_lock(&sfp->f_mutex);
 651         if (sfp->next_cmd_len > 0) {
 652                 cmd_size = sfp->next_cmd_len;
 653                 sfp->next_cmd_len = 0;  /* reset so only this write() effected */
 654         } else {
 655                 cmd_size = COMMAND_SIZE(opcode);        /* based on SCSI command group */
 656                 if ((opcode >= 0xc0) && old_hdr.twelve_byte)
 657                         cmd_size = 12;
 658         }
 659         mutex_unlock(&sfp->f_mutex);
 660         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
 661                 "sg_write:   scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
 662 /* Determine buffer size.  */
 663         input_size = count - cmd_size;
 664         mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
 665         mxsize -= SZ_SG_HEADER;
 666         input_size -= SZ_SG_HEADER;
 667         if (input_size < 0) {
 668                 sg_remove_request(sfp, srp);
 669                 return -EIO;    /* User did not pass enough bytes for this command. */
 670         }
 671         hp = &srp->header;
 672         hp->interface_id = '\0';        /* indicator of old interface tunnelled */
 673         hp->cmd_len = (unsigned char) cmd_size;
 674         hp->iovec_count = 0;
 675         hp->mx_sb_len = 0;
 676         if (input_size > 0)
 677                 hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
 678                     SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
 679         else
 680                 hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
 681         hp->dxfer_len = mxsize;
 682         if ((hp->dxfer_direction == SG_DXFER_TO_DEV) ||
 683             (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV))
 684                 hp->dxferp = (char __user *)buf + cmd_size;
 685         else
 686                 hp->dxferp = NULL;
 687         hp->sbp = NULL;
 688         hp->timeout = old_hdr.reply_len;        /* structure abuse ... */
 689         hp->flags = input_size; /* structure abuse ... */
 690         hp->pack_id = old_hdr.pack_id;
 691         hp->usr_ptr = NULL;
 692         if (__copy_from_user(cmnd, buf, cmd_size)) {
 693                 sg_remove_request(sfp, srp);
 694                 return -EFAULT;
 695         }
 696         /*
 697          * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
 698          * but is is possible that the app intended SG_DXFER_TO_DEV, because there
 699          * is a non-zero input_size, so emit a warning.
 700          */
 701         if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
 702                 printk_ratelimited(KERN_WARNING
 703                                    "sg_write: data in/out %d/%d bytes "
 704                                    "for SCSI command 0x%x-- guessing "
 705                                    "data in;\n   program %s not setting "
 706                                    "count and/or reply_len properly\n",
 707                                    old_hdr.reply_len - (int)SZ_SG_HEADER,
 708                                    input_size, (unsigned int) cmnd[0],
 709                                    current->comm);
 710         }
 711         k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
 712         return (k < 0) ? k : count;
 713 }
 714
 715 static ssize_t
 716 sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
 717                  size_t count, int blocking, int read_only, int sg_io_owned,
 718                  Sg_request **o_srp)
 719 {
 720         int k;
 721         Sg_request *srp;
 722         sg_io_hdr_t *hp;
 723         unsigned char cmnd[SG_MAX_CDB_SIZE];
 724         int timeout;
 725         unsigned long ul_timeout;
 726
 727         if (count < SZ_SG_IO_HDR)
 728                 return -EINVAL;
 729         if (!access_ok(VERIFY_READ, buf, count))
 730                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 731
 732         sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */
 733         if (!(srp = sg_add_request(sfp))) {
 734                 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
 735                                               "sg_new_write: queue full\n"));
 736                 return -EDOM;
 737         }
 738         srp->sg_io_owned = sg_io_owned;
 739         hp = &srp->header;
 740         if (__copy_from_user(hp, buf, SZ_SG_IO_HDR)) {
 741                 sg_remove_request(sfp, srp);
 742                 return -EFAULT;
 743         }
 744         if (hp->interface_id != 'S') {
 745                 sg_remove_request(sfp, srp);
 746                 return -ENOSYS;
 747         }
 748         if (hp->flags & SG_FLAG_MMAP_IO) {
 749                 if (hp->dxfer_len > sfp->reserve.bufflen) {
 750                         sg_remove_request(sfp, srp);
 751                         return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
 752                 }
 753                 if (hp->flags & SG_FLAG_DIRECT_IO) {
 754                         sg_remove_request(sfp, srp);
 755                         return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
 756                 }
 757                 if (sfp->res_in_use) {
 758                         sg_remove_request(sfp, srp);
 759                         return -EBUSY;  /* reserve buffer already being used */
 760                 }
 761         }
 762         ul_timeout = msecs_to_jiffies(srp->header.timeout);
 763         timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
 764         if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
 765                 sg_remove_request(sfp, srp);
 766                 return -EMSGSIZE;
 767         }
 768         if (!access_ok(VERIFY_READ, hp->cmdp, hp->cmd_len)) {
 769                 sg_remove_request(sfp, srp);
 770                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 771         }
 772         if (__copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
 773                 sg_remove_request(sfp, srp);
 774                 return -EFAULT;
 775         }
 776         if (read_only && sg_allow_access(file, cmnd)) {
 777                 sg_remove_request(sfp, srp);
 778                 return -EPERM;
 779         }
 780         k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
 781         if (k < 0)
 782                 return k;
 783         if (o_srp)
 784                 *o_srp = srp;
 785         return count;
 786 }
 787
 788 static int
 789 sg_common_write(Sg_fd * sfp, Sg_request * srp,
 790                 unsigned char *cmnd, int timeout, int blocking)
 791 {
 792         int k, at_head;
 793         Sg_device *sdp = sfp->parentdp;
 794         sg_io_hdr_t *hp = &srp->header;
 795
 796         srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
 797         hp->status = 0;
 798         hp->masked_status = 0;
 799         hp->msg_status = 0;
 800         hp->info = 0;
 801         hp->host_status = 0;
 802         hp->driver_status = 0;
 803         hp->resid = 0;
 804         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
 805                         "sg_common_write:  scsi opcode=0x%02x, cmd_size=%d\n",
 806                         (int) cmnd[0], (int) hp->cmd_len));
 807
 808         if (hp->dxfer_len >= SZ_256M) {
 809                 sg_remove_request(sfp, srp);
 810                 return -EINVAL;
 811         }
 812
 813         k = sg_start_req(srp, cmnd);
 814         if (k) {
 815                 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
 816                         "sg_common_write: start_req err=%d\n", k));
 817                 sg_finish_rem_req(srp);
 818                 sg_remove_request(sfp, srp);
 819                 return k;       /* probably out of space --> ENOMEM */
 820         }
 821         if (atomic_read(&sdp->detaching)) {
 822                 if (srp->bio) {
 823                         scsi_req_free_cmd(scsi_req(srp->rq));
 824                         blk_end_request_all(srp->rq, BLK_STS_IOERR);
 825                         srp->rq = NULL;
 826                 }
 827
 828                 sg_finish_rem_req(srp);
 829                 sg_remove_request(sfp, srp);
 830                 return -ENODEV;
 831         }
 832
 833         hp->duration = jiffies_to_msecs(jiffies);
 834         if (hp->interface_id != '\0' && /* v3 (or later) interface */
 835             (SG_FLAG_Q_AT_TAIL & hp->flags))
 836                 at_head = 0;
 837         else
 838                 at_head = 1;
 839
 840         srp->rq->timeout = timeout;
 841         kref_get(&sfp->f_ref); /* sg_rq_end_io() does kref_put(). */
 842         blk_execute_rq_nowait(sdp->device->request_queue, sdp->disk,
 843                               srp->rq, at_head, sg_rq_end_io);
 844         return 0;
 845 }
 846
 847 static int srp_done(Sg_fd *sfp, Sg_request *srp)
 848 {
 849         unsigned long flags;
 850         int ret;
 851
 852         read_lock_irqsave(&sfp->rq_list_lock, flags);
 853         ret = srp->done;
 854         read_unlock_irqrestore(&sfp->rq_list_lock, flags);
 855         return ret;
 856 }
 857
 858 static int max_sectors_bytes(struct request_queue *q)
 859 {
 860         unsigned int max_sectors = queue_max_sectors(q);
 861
 862         max_sectors = min_t(unsigned int, max_sectors, INT_MAX >> 9);
 863
 864         return max_sectors << 9;
 865 }
 866
 867 static void
 868 sg_fill_request_table(Sg_fd *sfp, sg_req_info_t *rinfo)
 869 {
 870         Sg_request *srp;
 871         int val;
 872         unsigned int ms;
 873
 874         val = 0;
 875         list_for_each_entry(srp, &sfp->rq_list, entry) {
 876                 if (val >= SG_MAX_QUEUE)
 877                         break;
 878                 rinfo[val].req_state = srp->done + 1;
 879                 rinfo[val].problem =
 880                         srp->header.masked_status &
 881                         srp->header.host_status &
 882                         srp->header.driver_status;
 883                 if (srp->done)
 884                         rinfo[val].duration =
 885                                 srp->header.duration;
 886                 else {
 887                         ms = jiffies_to_msecs(jiffies);
 888                         rinfo[val].duration =
 889                                 (ms > srp->header.duration) ?
 890                                 (ms - srp->header.duration) : 0;
 891                 }
 892                 rinfo[val].orphan = srp->orphan;
 893                 rinfo[val].sg_io_owned = srp->sg_io_owned;
 894                 rinfo[val].pack_id = srp->header.pack_id;
 895                 rinfo[val].usr_ptr = srp->header.usr_ptr;
 896                 val++;
 897         }
 898 }
 899
 900 static long
 901 sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
 902 {
 903         void __user *p = (void __user *)arg;
 904         int __user *ip = p;
 905         int result, val, read_only;
 906         Sg_device *sdp;
 907         Sg_fd *sfp;
 908         Sg_request *srp;
 909         unsigned long iflags;
 910
 911         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 912                 return -ENXIO;
 913
 914         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 915                                    "sg_ioctl: cmd=0x%x\n", (int) cmd_in));
 916         read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
 917
 918         switch (cmd_in) {
 919         case SG_IO:
 920                 if (atomic_read(&sdp->detaching))
 921                         return -ENODEV;
 922                 if (!scsi_block_when_processing_errors(sdp->device))
 923                         return -ENXIO;
 924                 if (!access_ok(VERIFY_WRITE, p, SZ_SG_IO_HDR))
 925                         return -EFAULT;
 926                 result = sg_new_write(sfp, filp, p, SZ_SG_IO_HDR,
 927                                  1, read_only, 1, &srp);
 928                 if (result < 0)
 929                         return result;
 930                 result = wait_event_interruptible(sfp->read_wait,
 931                         srp_done(sfp, srp));
 932                 write_lock_irq(&sfp->rq_list_lock);
 933                 if (srp->done) {
 934                         srp->done = 2;
 935                         write_unlock_irq(&sfp->rq_list_lock);
 936                         result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
 937                         return (result < 0) ? result : 0;
 938                 }
 939                 srp->orphan = 1;
 940                 write_unlock_irq(&sfp->rq_list_lock);
 941                 return result;  /* -ERESTARTSYS because signal hit process */
 942         case SG_SET_TIMEOUT:
 943                 result = get_user(val, ip);
 944                 if (result)
 945                         return result;
 946                 if (val < 0)
 947                         return -EIO;
 948                 if (val >= mult_frac((s64)INT_MAX, USER_HZ, HZ))
 949                         val = min_t(s64, mult_frac((s64)INT_MAX, USER_HZ, HZ),
 950                                     INT_MAX);
 951                 sfp->timeout_user = val;
 952                 sfp->timeout = mult_frac(val, HZ, USER_HZ);
 953
 954                 return 0;
 955         case SG_GET_TIMEOUT:    /* N.B. User receives timeout as return value */
 956                                 /* strange ..., for backward compatibility */
 957                 return sfp->timeout_user;
 958         case SG_SET_FORCE_LOW_DMA:
 959                 /*
 960                  * N.B. This ioctl never worked properly, but failed to
 961                  * return an error value. So returning '0' to keep compability
 962                  * with legacy applications.
 963                  */
 964                 return 0;
 965         case SG_GET_LOW_DMA:
 966                 return put_user((int) sdp->device->host->unchecked_isa_dma, ip);
 967         case SG_GET_SCSI_ID:
 968                 if (!access_ok(VERIFY_WRITE, p, sizeof (sg_scsi_id_t)))
 969                         return -EFAULT;
 970                 else {
 971                         sg_scsi_id_t __user *sg_idp = p;
 972
 973                         if (atomic_read(&sdp->detaching))
 974                                 return -ENODEV;
 975                         __put_user((int) sdp->device->host->host_no,
 976                                    &sg_idp->host_no);
 977                         __put_user((int) sdp->device->channel,
 978                                    &sg_idp->channel);
 979                         __put_user((int) sdp->device->id, &sg_idp->scsi_id);
 980                         __put_user((int) sdp->device->lun, &sg_idp->lun);
 981                         __put_user((int) sdp->device->type, &sg_idp->scsi_type);
 982                         __put_user((short) sdp->device->host->cmd_per_lun,
 983                                    &sg_idp->h_cmd_per_lun);
 984                         __put_user((short) sdp->device->queue_depth,
 985                                    &sg_idp->d_queue_depth);
 986                         __put_user(0, &sg_idp->unused[0]);
 987                         __put_user(0, &sg_idp->unused[1]);
 988                         return 0;
 989                 }
 990         case SG_SET_FORCE_PACK_ID:
 991                 result = get_user(val, ip);
 992                 if (result)
 993                         return result;
 994                 sfp->force_packid = val ? 1 : 0;
 995                 return 0;
 996         case SG_GET_PACK_ID:
 997                 if (!access_ok(VERIFY_WRITE, ip, sizeof (int)))
 998                         return -EFAULT;
 999                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
1000                 list_for_each_entry(srp, &sfp->rq_list, entry) {
1001                         if ((1 == srp->done) && (!srp->sg_io_owned)) {
1002                                 read_unlock_irqrestore(&sfp->rq_list_lock,
1003                                                        iflags);
1004                                 __put_user(srp->header.pack_id, ip);
1005                                 return 0;
1006                         }
1007                 }
1008                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1009                 __put_user(-1, ip);
1010                 return 0;
1011         case SG_GET_NUM_WAITING:
1012                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
1013                 val = 0;
1014                 list_for_each_entry(srp, &sfp->rq_list, entry) {
1015                         if ((1 == srp->done) && (!srp->sg_io_owned))
1016                                 ++val;
1017                 }
1018                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1019                 return put_user(val, ip);
1020         case SG_GET_SG_TABLESIZE:
1021                 return put_user(sdp->sg_tablesize, ip);
1022         case SG_SET_RESERVED_SIZE:
1023                 result = get_user(val, ip);
1024                 if (result)
1025                         return result;
1026                 if (val < 0)
1027                         return -EINVAL;
1028                 val = min_t(int, val,
1029                             max_sectors_bytes(sdp->device->request_queue));
1030                 mutex_lock(&sfp->f_mutex);
1031                 if (val != sfp->reserve.bufflen) {
1032                         if (sfp->mmap_called ||
1033                             sfp->res_in_use) {
1034                                 mutex_unlock(&sfp->f_mutex);
1035                                 return -EBUSY;
1036                         }
1037
1038                         sg_remove_scat(sfp, &sfp->reserve);
1039                         sg_build_reserve(sfp, val);
1040                 }
1041                 mutex_unlock(&sfp->f_mutex);
1042                 return 0;
1043         case SG_GET_RESERVED_SIZE:
1044                 val = min_t(int, sfp->reserve.bufflen,
1045                             max_sectors_bytes(sdp->device->request_queue));
1046                 return put_user(val, ip);
1047         case SG_SET_COMMAND_Q:
1048                 result = get_user(val, ip);
1049                 if (result)
1050                         return result;
1051                 sfp->cmd_q = val ? 1 : 0;
1052                 return 0;
1053         case SG_GET_COMMAND_Q:
1054                 return put_user((int) sfp->cmd_q, ip);
1055         case SG_SET_KEEP_ORPHAN:
1056                 result = get_user(val, ip);
1057                 if (result)
1058                         return result;
1059                 sfp->keep_orphan = val;
1060                 return 0;
1061         case SG_GET_KEEP_ORPHAN:
1062                 return put_user((int) sfp->keep_orphan, ip);
1063         case SG_NEXT_CMD_LEN:
1064                 result = get_user(val, ip);
1065                 if (result)
1066                         return result;
1067                 if (val > SG_MAX_CDB_SIZE)
1068                         return -ENOMEM;
1069                 sfp->next_cmd_len = (val > 0) ? val : 0;
1070                 return 0;
1071         case SG_GET_VERSION_NUM:
1072                 return put_user(sg_version_num, ip);
1073         case SG_GET_ACCESS_COUNT:
1074                 /* faked - we don't have a real access count anymore */
1075                 val = (sdp->device ? 1 : 0);
1076                 return put_user(val, ip);
1077         case SG_GET_REQUEST_TABLE:
1078                 if (!access_ok(VERIFY_WRITE, p, SZ_SG_REQ_INFO * SG_MAX_QUEUE))
1079                         return -EFAULT;
1080                 else {
1081                         sg_req_info_t *rinfo;
1082
1083                         rinfo = kcalloc(SG_MAX_QUEUE, SZ_SG_REQ_INFO,
1084                                         GFP_KERNEL);
1085                         if (!rinfo)
1086                                 return -ENOMEM;
1087                         read_lock_irqsave(&sfp->rq_list_lock, iflags);
1088                         sg_fill_request_table(sfp, rinfo);
1089                         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1090                         result = __copy_to_user(p, rinfo,
1091                                                 SZ_SG_REQ_INFO * SG_MAX_QUEUE);
1092                         result = result ? -EFAULT : 0;
1093                         kfree(rinfo);
1094                         return result;
1095                 }
1096         case SG_EMULATED_HOST:
1097                 if (atomic_read(&sdp->detaching))
1098                         return -ENODEV;
1099                 return put_user(sdp->device->host->hostt->emulated, ip);
1100         case SCSI_IOCTL_SEND_COMMAND:
1101                 if (atomic_read(&sdp->detaching))
1102                         return -ENODEV;
1103                 return sg_scsi_ioctl(sdp->device->request_queue, NULL, filp->f_mode, p);
1104         case SG_SET_DEBUG:
1105                 result = get_user(val, ip);
1106                 if (result)
1107                         return result;
1108                 sdp->sgdebug = (char) val;
1109                 return 0;
1110         case BLKSECTGET:
1111                 return put_user(max_sectors_bytes(sdp->device->request_queue),
1112                                 ip);
1113         case BLKTRACESETUP:
1114                 return blk_trace_setup(sdp->device->request_queue,
1115                                        sdp->disk->disk_name,
1116                                        MKDEV(SCSI_GENERIC_MAJOR, sdp->index),
1117                                        NULL, p);
1118         case BLKTRACESTART:
1119                 return blk_trace_startstop(sdp->device->request_queue, 1);
1120         case BLKTRACESTOP:
1121                 return blk_trace_startstop(sdp->device->request_queue, 0);
1122         case BLKTRACETEARDOWN:
1123                 return blk_trace_remove(sdp->device->request_queue);
1124         case SCSI_IOCTL_GET_IDLUN:
1125         case SCSI_IOCTL_GET_BUS_NUMBER:
1126         case SCSI_IOCTL_PROBE_HOST:
1127         case SG_GET_TRANSFORM:
1128         case SG_SCSI_RESET:
1129                 if (atomic_read(&sdp->detaching))
1130                         return -ENODEV;
1131                 break;
1132         default:
1133                 if (read_only)
1134                         return -EPERM;  /* don't know so take safe approach */
1135                 break;
1136         }
1137
1138         result = scsi_ioctl_block_when_processing_errors(sdp->device,
1139                         cmd_in, filp->f_flags & O_NDELAY);
1140         if (result)
1141                 return result;
1142         return scsi_ioctl(sdp->device, cmd_in, p);
1143 }
1144
1145 #ifdef CONFIG_COMPAT
1146 static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1147 {
1148         Sg_device *sdp;
1149         Sg_fd *sfp;
1150         struct scsi_device *sdev;
1151
1152         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1153                 return -ENXIO;
1154
1155         sdev = sdp->device;
1156         if (sdev->host->hostt->compat_ioctl) {
1157                 int ret;
1158
1159                 ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void __user *)arg);
1160
1161                 return ret;
1162         }
1163
1164         return -ENOIOCTLCMD;
1165 }
1166 #endif
1167
1168 static __poll_t
1169 sg_poll(struct file *filp, poll_table * wait)
1170 {
1171         __poll_t res = 0;
1172         Sg_device *sdp;
1173         Sg_fd *sfp;
1174         Sg_request *srp;
1175         int count = 0;
1176         unsigned long iflags;
1177
1178         sfp = filp->private_data;
1179         if (!sfp)
1180                 return EPOLLERR;
1181         sdp = sfp->parentdp;
1182         if (!sdp)
1183                 return EPOLLERR;
1184         poll_wait(filp, &sfp->read_wait, wait);
1185         read_lock_irqsave(&sfp->rq_list_lock, iflags);
1186         list_for_each_entry(srp, &sfp->rq_list, entry) {
1187                 /* if any read waiting, flag it */
1188                 if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1189                         res = EPOLLIN | EPOLLRDNORM;
1190                 ++count;
1191         }
1192         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1193
1194         if (atomic_read(&sdp->detaching))
1195                 res |= EPOLLHUP;
1196         else if (!sfp->cmd_q) {
1197                 if (0 == count)
1198                         res |= EPOLLOUT | EPOLLWRNORM;
1199         } else if (count < SG_MAX_QUEUE)
1200                 res |= EPOLLOUT | EPOLLWRNORM;
1201         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1202                                       "sg_poll: res=0x%x\n", (__force u32) res));
1203         return res;
1204 }
1205
1206 static int
1207 sg_fasync(int fd, struct file *filp, int mode)
1208 {
1209         Sg_device *sdp;
1210         Sg_fd *sfp;
1211
1212         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1213                 return -ENXIO;
1214         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1215                                       "sg_fasync: mode=%d\n", mode));
1216
1217         return fasync_helper(fd, filp, mode, &sfp->async_qp);
1218 }
1219
1220 static vm_fault_t
1221 sg_vma_fault(struct vm_fault *vmf)
1222 {
1223         struct vm_area_struct *vma = vmf->vma;
1224         Sg_fd *sfp;
1225         unsigned long offset, len, sa;
1226         Sg_scatter_hold *rsv_schp;
1227         int k, length;
1228
1229         if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1230                 return VM_FAULT_SIGBUS;
1231         rsv_schp = &sfp->reserve;
1232         offset = vmf->pgoff << PAGE_SHIFT;
1233         if (offset >= rsv_schp->bufflen)
1234                 return VM_FAULT_SIGBUS;
1235         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1236                                       "sg_vma_fault: offset=%lu, scatg=%d\n",
1237                                       offset, rsv_schp->k_use_sg));
1238         sa = vma->vm_start;
1239         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1240         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1241                 len = vma->vm_end - sa;
1242                 len = (len < length) ? len : length;
1243                 if (offset < len) {
1244                         struct page *page = nth_page(rsv_schp->pages[k],
1245                                                      offset >> PAGE_SHIFT);
1246                         get_page(page); /* increment page count */
1247                         vmf->page = page;
1248                         return 0; /* success */
1249                 }
1250                 sa += len;
1251                 offset -= len;
1252         }
1253
1254         return VM_FAULT_SIGBUS;
1255 }
1256
1257 static const struct vm_operations_struct sg_mmap_vm_ops = {
1258         .fault = sg_vma_fault,
1259 };
1260
1261 static int
1262 sg_mmap(struct file *filp, struct vm_area_struct *vma)
1263 {
1264         Sg_fd *sfp;
1265         unsigned long req_sz, len, sa;
1266         Sg_scatter_hold *rsv_schp;
1267         int k, length;
1268         int ret = 0;
1269
1270         if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1271                 return -ENXIO;
1272         req_sz = vma->vm_end - vma->vm_start;
1273         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1274                                       "sg_mmap starting, vm_start=%p, len=%d\n",
1275                                       (void *) vma->vm_start, (int) req_sz));
1276         if (vma->vm_pgoff)
1277                 return -EINVAL; /* want no offset */
1278         rsv_schp = &sfp->reserve;
1279         mutex_lock(&sfp->f_mutex);
1280         if (req_sz > rsv_schp->bufflen) {
1281                 ret = -ENOMEM;  /* cannot map more than reserved buffer */
1282                 goto out;
1283         }
1284
1285         sa = vma->vm_start;
1286         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1287         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1288                 len = vma->vm_end - sa;
1289                 len = (len < length) ? len : length;
1290                 sa += len;
1291         }
1292
1293         sfp->mmap_called = 1;
1294         vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP;
1295         vma->vm_private_data = sfp;
1296         vma->vm_ops = &sg_mmap_vm_ops;
1297 out:
1298         mutex_unlock(&sfp->f_mutex);
1299         return ret;
1300 }
1301
1302 static void
1303 sg_rq_end_io_usercontext(struct work_struct *work)
1304 {
1305         struct sg_request *srp = container_of(work, struct sg_request, ew.work);
1306         struct sg_fd *sfp = srp->parentfp;
1307
1308         sg_finish_rem_req(srp);
1309         sg_remove_request(sfp, srp);
1310         kref_put(&sfp->f_ref, sg_remove_sfp);
1311 }
1312
1313 /*
1314  * This function is a "bottom half" handler that is called by the mid
1315  * level when a command is completed (or has failed).
1316  */
1317 static void
1318 sg_rq_end_io(struct request *rq, blk_status_t status)
1319 {
1320         struct sg_request *srp = rq->end_io_data;
1321         struct scsi_request *req = scsi_req(rq);
1322         Sg_device *sdp;
1323         Sg_fd *sfp;
1324         unsigned long iflags;
1325         unsigned int ms;
1326         char *sense;
1327         int result, resid, done = 1;
1328
1329         if (WARN_ON(srp->done != 0))
1330                 return;
1331
1332         sfp = srp->parentfp;
1333         if (WARN_ON(sfp == NULL))
1334                 return;
1335
1336         sdp = sfp->parentdp;
1337         if (unlikely(atomic_read(&sdp->detaching)))
1338                 pr_info("%s: device detaching\n", __func__);
1339
1340         sense = req->sense;
1341         result = req->result;
1342         resid = req->resid_len;
1343
1344         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
1345                                       "sg_cmd_done: pack_id=%d, res=0x%x\n",
1346                                       srp->header.pack_id, result));
1347         srp->header.resid = resid;
1348         ms = jiffies_to_msecs(jiffies);
1349         srp->header.duration = (ms > srp->header.duration) ?
1350                                 (ms - srp->header.duration) : 0;
1351         if (0 != result) {
1352                 struct scsi_sense_hdr sshdr;
1353
1354                 srp->header.status = 0xff & result;
1355                 srp->header.masked_status = status_byte(result);
1356                 srp->header.msg_status = msg_byte(result);
1357                 srp->header.host_status = host_byte(result);
1358                 srp->header.driver_status = driver_byte(result);
1359                 if ((sdp->sgdebug > 0) &&
1360                     ((CHECK_CONDITION == srp->header.masked_status) ||
1361                      (COMMAND_TERMINATED == srp->header.masked_status)))
1362                         __scsi_print_sense(sdp->device, __func__, sense,
1363                                            SCSI_SENSE_BUFFERSIZE);
1364
1365                 /* Following if statement is a patch supplied by Eric Youngdale */
1366                 if (driver_byte(result) != 0
1367                     && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1368                     && !scsi_sense_is_deferred(&sshdr)
1369                     && sshdr.sense_key == UNIT_ATTENTION
1370                     && sdp->device->removable) {
1371                         /* Detected possible disc change. Set the bit - this */
1372                         /* may be used if there are filesystems using this device */
1373                         sdp->device->changed = 1;
1374                 }
1375         }
1376
1377         if (req->sense_len)
1378                 memcpy(srp->sense_b, req->sense, SCSI_SENSE_BUFFERSIZE);
1379
1380         /* Rely on write phase to clean out srp status values, so no "else" */
1381
1382         /*
1383          * Free the request as soon as it is complete so that its resources
1384          * can be reused without waiting for userspace to read() the
1385          * result.  But keep the associated bio (if any) around until
1386          * blk_rq_unmap_user() can be called from user context.
1387          */
1388         srp->rq = NULL;
1389         scsi_req_free_cmd(scsi_req(rq));
1390         __blk_put_request(rq->q, rq);
1391
1392         write_lock_irqsave(&sfp->rq_list_lock, iflags);
1393         if (unlikely(srp->orphan)) {
1394                 if (sfp->keep_orphan)
1395                         srp->sg_io_owned = 0;
1396                 else
1397                         done = 0;
1398         }
1399         srp->done = done;
1400         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1401
1402         if (likely(done)) {
1403                 /* Now wake up any sg_read() that is waiting for this
1404                  * packet.
1405                  */
1406                 wake_up_interruptible(&sfp->read_wait);
1407                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1408                 kref_put(&sfp->f_ref, sg_remove_sfp);
1409         } else {
1410                 INIT_WORK(&srp->ew.work, sg_rq_end_io_usercontext);
1411                 schedule_work(&srp->ew.work);
1412         }
1413 }
1414
1415 static const struct file_operations sg_fops = {
1416         .owner = THIS_MODULE,
1417         .read = sg_read,
1418         .write = sg_write,
1419         .poll = sg_poll,
1420         .unlocked_ioctl = sg_ioctl,
1421 #ifdef CONFIG_COMPAT
1422         .compat_ioctl = sg_compat_ioctl,
1423 #endif
1424         .open = sg_open,
1425         .mmap = sg_mmap,
1426         .release = sg_release,
1427         .fasync = sg_fasync,
1428         .llseek = no_llseek,
1429 };
1430
1431 static struct class *sg_sysfs_class;
1432
1433 static int sg_sysfs_valid = 0;
1434
1435 static Sg_device *
1436 sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1437 {
1438         struct request_queue *q = scsidp->request_queue;
1439         Sg_device *sdp;
1440         unsigned long iflags;
1441         int error;
1442         u32 k;
1443
1444         sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1445         if (!sdp) {
1446                 sdev_printk(KERN_WARNING, scsidp, "%s: kmalloc Sg_device "
1447                             "failure\n", __func__);
1448                 return ERR_PTR(-ENOMEM);
1449         }
1450
1451         idr_preload(GFP_KERNEL);
1452         write_lock_irqsave(&sg_index_lock, iflags);
1453
1454         error = idr_alloc(&sg_index_idr, sdp, 0, SG_MAX_DEVS, GFP_NOWAIT);
1455         if (error < 0) {
1456                 if (error == -ENOSPC) {
1457                         sdev_printk(KERN_WARNING, scsidp,
1458                                     "Unable to attach sg device type=%d, minor number exceeds %d\n",
1459                                     scsidp->type, SG_MAX_DEVS - 1);
1460                         error = -ENODEV;
1461                 } else {
1462                         sdev_printk(KERN_WARNING, scsidp, "%s: idr "
1463                                     "allocation Sg_device failure: %d\n",
1464                                     __func__, error);
1465                 }
1466                 goto out_unlock;
1467         }
1468         k = error;
1469
1470         SCSI_LOG_TIMEOUT(3, sdev_printk(KERN_INFO, scsidp,
1471                                         "sg_alloc: dev=%d \n", k));
1472         sprintf(disk->disk_name, "sg%d", k);
1473         disk->first_minor = k;
1474         sdp->disk = disk;
1475         sdp->device = scsidp;
1476         mutex_init(&sdp->open_rel_lock);
1477         INIT_LIST_HEAD(&sdp->sfds);
1478         init_waitqueue_head(&sdp->open_wait);
1479         atomic_set(&sdp->detaching, 0);
1480         rwlock_init(&sdp->sfd_lock);
1481         sdp->sg_tablesize = queue_max_segments(q);
1482         sdp->index = k;
1483         kref_init(&sdp->d_ref);
1484         error = 0;
1485
1486 out_unlock:
1487         write_unlock_irqrestore(&sg_index_lock, iflags);
1488         idr_preload_end();
1489
1490         if (error) {
1491                 kfree(sdp);
1492                 return ERR_PTR(error);
1493         }
1494         return sdp;
1495 }
1496
1497 static int
1498 sg_add_device(struct device *cl_dev, struct class_interface *cl_intf)
1499 {
1500         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1501         struct gendisk *disk;
1502         Sg_device *sdp = NULL;
1503         struct cdev * cdev = NULL;
1504         int error;
1505         unsigned long iflags;
1506
1507         disk = alloc_disk(1);
1508         if (!disk) {
1509                 pr_warn("%s: alloc_disk failed\n", __func__);
1510                 return -ENOMEM;
1511         }
1512         disk->major = SCSI_GENERIC_MAJOR;
1513
1514         error = -ENOMEM;
1515         cdev = cdev_alloc();
1516         if (!cdev) {
1517                 pr_warn("%s: cdev_alloc failed\n", __func__);
1518                 goto out;
1519         }
1520         cdev->owner = THIS_MODULE;
1521         cdev->ops = &sg_fops;
1522
1523         sdp = sg_alloc(disk, scsidp);
1524         if (IS_ERR(sdp)) {
1525                 pr_warn("%s: sg_alloc failed\n", __func__);
1526                 error = PTR_ERR(sdp);
1527                 goto out;
1528         }
1529
1530         error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1);
1531         if (error)
1532                 goto cdev_add_err;
1533
1534         sdp->cdev = cdev;
1535         if (sg_sysfs_valid) {
1536                 struct device *sg_class_member;
1537
1538                 sg_class_member = device_create(sg_sysfs_class, cl_dev->parent,
1539                                                 MKDEV(SCSI_GENERIC_MAJOR,
1540                                                       sdp->index),
1541                                                 sdp, "%s", disk->disk_name);
1542                 if (IS_ERR(sg_class_member)) {
1543                         pr_err("%s: device_create failed\n", __func__);
1544                         error = PTR_ERR(sg_class_member);
1545                         goto cdev_add_err;
1546                 }
1547                 error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1548                                           &sg_class_member->kobj, "generic");
1549                 if (error)
1550                         pr_err("%s: unable to make symlink 'generic' back "
1551                                "to sg%d\n", __func__, sdp->index);
1552         } else
1553                 pr_warn("%s: sg_sys Invalid\n", __func__);
1554
1555         sdev_printk(KERN_NOTICE, scsidp, "Attached scsi generic sg%d "
1556                     "type %d\n", sdp->index, scsidp->type);
1557
1558         dev_set_drvdata(cl_dev, sdp);
1559
1560         return 0;
1561
1562 cdev_add_err:
1563         write_lock_irqsave(&sg_index_lock, iflags);
1564         idr_remove(&sg_index_idr, sdp->index);
1565         write_unlock_irqrestore(&sg_index_lock, iflags);
1566         kfree(sdp);
1567
1568 out:
1569         put_disk(disk);
1570         if (cdev)
1571                 cdev_del(cdev);
1572         return error;
1573 }
1574
1575 static void
1576 sg_device_destroy(struct kref *kref)
1577 {
1578         struct sg_device *sdp = container_of(kref, struct sg_device, d_ref);
1579         unsigned long flags;
1580
1581         /* CAUTION!  Note that the device can still be found via idr_find()
1582          * even though the refcount is 0.  Therefore, do idr_remove() BEFORE
1583          * any other cleanup.
1584          */
1585
1586         write_lock_irqsave(&sg_index_lock, flags);
1587         idr_remove(&sg_index_idr, sdp->index);
1588         write_unlock_irqrestore(&sg_index_lock, flags);
1589
1590         SCSI_LOG_TIMEOUT(3,
1591                 sg_printk(KERN_INFO, sdp, "sg_device_destroy\n"));
1592
1593         put_disk(sdp->disk);
1594         kfree(sdp);
1595 }
1596
1597 static void
1598 sg_remove_device(struct device *cl_dev, struct class_interface *cl_intf)
1599 {
1600         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1601         Sg_device *sdp = dev_get_drvdata(cl_dev);
1602         unsigned long iflags;
1603         Sg_fd *sfp;
1604         int val;
1605
1606         if (!sdp)
1607                 return;
1608         /* want sdp->detaching non-zero as soon as possible */
1609         val = atomic_inc_return(&sdp->detaching);
1610         if (val > 1)
1611                 return; /* only want to do following once per device */
1612
1613         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1614                                       "%s\n", __func__));
1615
1616         read_lock_irqsave(&sdp->sfd_lock, iflags);
1617         list_for_each_entry(sfp, &sdp->sfds, sfd_siblings) {
1618                 wake_up_interruptible_all(&sfp->read_wait);
1619                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_HUP);
1620         }
1621         wake_up_interruptible_all(&sdp->open_wait);
1622         read_unlock_irqrestore(&sdp->sfd_lock, iflags);
1623
1624         sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1625         device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index));
1626         cdev_del(sdp->cdev);
1627         sdp->cdev = NULL;
1628
1629         kref_put(&sdp->d_ref, sg_device_destroy);
1630 }
1631
1632 module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
1633 module_param_named(def_reserved_size, def_reserved_size, int,
1634                    S_IRUGO | S_IWUSR);
1635 module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1636
1637 MODULE_AUTHOR("Douglas Gilbert");
1638 MODULE_DESCRIPTION("SCSI generic (sg) driver");
1639 MODULE_LICENSE("GPL");
1640 MODULE_VERSION(SG_VERSION_STR);
1641 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1642
1643 MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
1644                 "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
1645 MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1646 MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1647
1648 static int __init
1649 init_sg(void)
1650 {
1651         int rc;
1652
1653         if (scatter_elem_sz < PAGE_SIZE) {
1654                 scatter_elem_sz = PAGE_SIZE;
1655                 scatter_elem_sz_prev = scatter_elem_sz;
1656         }
1657         if (def_reserved_size >= 0)
1658                 sg_big_buff = def_reserved_size;
1659         else
1660                 def_reserved_size = sg_big_buff;
1661
1662         rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1663                                     SG_MAX_DEVS, "sg");
1664         if (rc)
1665                 return rc;
1666         sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1667         if ( IS_ERR(sg_sysfs_class) ) {
1668                 rc = PTR_ERR(sg_sysfs_class);
1669                 goto err_out;
1670         }
1671         sg_sysfs_valid = 1;
1672         rc = scsi_register_interface(&sg_interface);
1673         if (0 == rc) {
1674 #ifdef CONFIG_SCSI_PROC_FS
1675                 sg_proc_init();
1676 #endif                          /* CONFIG_SCSI_PROC_FS */
1677                 return 0;
1678         }
1679         class_destroy(sg_sysfs_class);
1680 err_out:
1681         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1682         return rc;
1683 }
1684
1685 static void __exit
1686 exit_sg(void)
1687 {
1688 #ifdef CONFIG_SCSI_PROC_FS
1689         remove_proc_subtree("scsi/sg", NULL);
1690 #endif                          /* CONFIG_SCSI_PROC_FS */
1691         scsi_unregister_interface(&sg_interface);
1692         class_destroy(sg_sysfs_class);
1693         sg_sysfs_valid = 0;
1694         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1695                                  SG_MAX_DEVS);
1696         idr_destroy(&sg_index_idr);
1697 }
1698
1699 static int
1700 sg_start_req(Sg_request *srp, unsigned char *cmd)
1701 {
1702         int res;
1703         struct request *rq;
1704         struct scsi_request *req;
1705         Sg_fd *sfp = srp->parentfp;
1706         sg_io_hdr_t *hp = &srp->header;
1707         int dxfer_len = (int) hp->dxfer_len;
1708         int dxfer_dir = hp->dxfer_direction;
1709         unsigned int iov_count = hp->iovec_count;
1710         Sg_scatter_hold *req_schp = &srp->data;
1711         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1712         struct request_queue *q = sfp->parentdp->device->request_queue;
1713         struct rq_map_data *md, map_data;
1714         int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? WRITE : READ;
1715         unsigned char *long_cmdp = NULL;
1716
1717         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1718                                       "sg_start_req: dxfer_len=%d\n",
1719                                       dxfer_len));
1720
1721         if (hp->cmd_len > BLK_MAX_CDB) {
1722                 long_cmdp = kzalloc(hp->cmd_len, GFP_KERNEL);
1723                 if (!long_cmdp)
1724                         return -ENOMEM;
1725         }
1726
1727         /*
1728          * NOTE
1729          *
1730          * With scsi-mq enabled, there are a fixed number of preallocated
1731          * requests equal in number to shost->can_queue.  If all of the
1732          * preallocated requests are already in use, then blk_get_request()
1733          * will sleep until an active command completes, freeing up a request.
1734          * Although waiting in an asynchronous interface is less than ideal, we
1735          * do not want to use BLK_MQ_REQ_NOWAIT here because userspace might
1736          * not expect an EWOULDBLOCK from this condition.
1737          */
1738         rq = blk_get_request(q, hp->dxfer_direction == SG_DXFER_TO_DEV ?
1739                         REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, 0);
1740         if (IS_ERR(rq)) {
1741                 kfree(long_cmdp);
1742                 return PTR_ERR(rq);
1743         }
1744         req = scsi_req(rq);
1745
1746         if (hp->cmd_len > BLK_MAX_CDB)
1747                 req->cmd = long_cmdp;
1748         memcpy(req->cmd, cmd, hp->cmd_len);
1749         req->cmd_len = hp->cmd_len;
1750
1751         srp->rq = rq;
1752         rq->end_io_data = srp;
1753         req->retries = SG_DEFAULT_RETRIES;
1754
1755         if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1756                 return 0;
1757
1758         if (sg_allow_dio && hp->flags & SG_FLAG_DIRECT_IO &&
1759             dxfer_dir != SG_DXFER_UNKNOWN && !iov_count &&
1760             !sfp->parentdp->device->host->unchecked_isa_dma &&
1761             blk_rq_aligned(q, (unsigned long)hp->dxferp, dxfer_len))
1762                 md = NULL;
1763         else
1764                 md = &map_data;
1765
1766         if (md) {
1767                 mutex_lock(&sfp->f_mutex);
1768                 if (dxfer_len <= rsv_schp->bufflen &&
1769                     !sfp->res_in_use) {
1770                         sfp->res_in_use = 1;
1771                         sg_link_reserve(sfp, srp, dxfer_len);
1772                 } else if (hp->flags & SG_FLAG_MMAP_IO) {
1773                         res = -EBUSY; /* sfp->res_in_use == 1 */
1774                         if (dxfer_len > rsv_schp->bufflen)
1775                                 res = -ENOMEM;
1776                         mutex_unlock(&sfp->f_mutex);
1777                         return res;
1778                 } else {
1779                         res = sg_build_indirect(req_schp, sfp, dxfer_len);
1780                         if (res) {
1781                                 mutex_unlock(&sfp->f_mutex);
1782                                 return res;
1783                         }
1784                 }
1785                 mutex_unlock(&sfp->f_mutex);
1786
1787                 md->pages = req_schp->pages;
1788                 md->page_order = req_schp->page_order;
1789                 md->nr_entries = req_schp->k_use_sg;
1790                 md->offset = 0;
1791                 md->null_mapped = hp->dxferp ? 0 : 1;
1792                 if (dxfer_dir == SG_DXFER_TO_FROM_DEV)
1793                         md->from_user = 1;
1794                 else
1795                         md->from_user = 0;
1796         }
1797
1798         if (iov_count) {
1799                 struct iovec *iov = NULL;
1800                 struct iov_iter i;
1801
1802                 res = import_iovec(rw, hp->dxferp, iov_count, 0, &iov, &i);
1803                 if (res < 0)
1804                         return res;
1805
1806                 iov_iter_truncate(&i, hp->dxfer_len);
1807                 if (!iov_iter_count(&i)) {
1808                         kfree(iov);
1809                         return -EINVAL;
1810                 }
1811
1812                 res = blk_rq_map_user_iov(q, rq, md, &i, GFP_ATOMIC);
1813                 kfree(iov);
1814         } else
1815                 res = blk_rq_map_user(q, rq, md, hp->dxferp,
1816                                       hp->dxfer_len, GFP_ATOMIC);
1817
1818         if (!res) {
1819                 srp->bio = rq->bio;
1820
1821                 if (!md) {
1822                         req_schp->dio_in_use = 1;
1823                         hp->info |= SG_INFO_DIRECT_IO;
1824                 }
1825         }
1826         return res;
1827 }
1828
1829 static int
1830 sg_finish_rem_req(Sg_request *srp)
1831 {
1832         int ret = 0;
1833
1834         Sg_fd *sfp = srp->parentfp;
1835         Sg_scatter_hold *req_schp = &srp->data;
1836
1837         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1838                                       "sg_finish_rem_req: res_used=%d\n",
1839                                       (int) srp->res_used));
1840         if (srp->bio)
1841                 ret = blk_rq_unmap_user(srp->bio);
1842
1843         if (srp->rq) {
1844                 scsi_req_free_cmd(scsi_req(srp->rq));
1845                 blk_put_request(srp->rq);
1846         }
1847
1848         if (srp->res_used)
1849                 sg_unlink_reserve(sfp, srp);
1850         else
1851                 sg_remove_scat(sfp, req_schp);
1852
1853         return ret;
1854 }
1855
1856 static int
1857 sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1858 {
1859         int sg_bufflen = tablesize * sizeof(struct page *);
1860         gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1861
1862         schp->pages = kzalloc(sg_bufflen, gfp_flags);
1863         if (!schp->pages)
1864                 return -ENOMEM;
1865         schp->sglist_len = sg_bufflen;
1866         return tablesize;       /* number of scat_gath elements allocated */
1867 }
1868
1869 static int
1870 sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1871 {
1872         int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
1873         int sg_tablesize = sfp->parentdp->sg_tablesize;
1874         int blk_size = buff_size, order;
1875         gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN | __GFP_ZERO;
1876         struct sg_device *sdp = sfp->parentdp;
1877
1878         if (blk_size < 0)
1879                 return -EFAULT;
1880         if (0 == blk_size)
1881                 ++blk_size;     /* don't know why */
1882         /* round request up to next highest SG_SECTOR_SZ byte boundary */
1883         blk_size = ALIGN(blk_size, SG_SECTOR_SZ);
1884         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1885                 "sg_build_indirect: buff_size=%d, blk_size=%d\n",
1886                 buff_size, blk_size));
1887
1888         /* N.B. ret_sz carried into this block ... */
1889         mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1890         if (mx_sc_elems < 0)
1891                 return mx_sc_elems;     /* most likely -ENOMEM */
1892
1893         num = scatter_elem_sz;
1894         if (unlikely(num != scatter_elem_sz_prev)) {
1895                 if (num < PAGE_SIZE) {
1896                         scatter_elem_sz = PAGE_SIZE;
1897                         scatter_elem_sz_prev = PAGE_SIZE;
1898                 } else
1899                         scatter_elem_sz_prev = num;
1900         }
1901
1902         if (sdp->device->host->unchecked_isa_dma)
1903                 gfp_mask |= GFP_DMA;
1904
1905         order = get_order(num);
1906 retry:
1907         ret_sz = 1 << (PAGE_SHIFT + order);
1908
1909         for (k = 0, rem_sz = blk_size; rem_sz > 0 && k < mx_sc_elems;
1910              k++, rem_sz -= ret_sz) {
1911
1912                 num = (rem_sz > scatter_elem_sz_prev) ?
1913                         scatter_elem_sz_prev : rem_sz;
1914
1915                 schp->pages[k] = alloc_pages(gfp_mask, order);
1916                 if (!schp->pages[k])
1917                         goto out;
1918
1919                 if (num == scatter_elem_sz_prev) {
1920                         if (unlikely(ret_sz > scatter_elem_sz_prev)) {
1921                                 scatter_elem_sz = ret_sz;
1922                                 scatter_elem_sz_prev = ret_sz;
1923                         }
1924                 }
1925
1926                 SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1927                                  "sg_build_indirect: k=%d, num=%d, ret_sz=%d\n",
1928                                  k, num, ret_sz));
1929         }               /* end of for loop */
1930
1931         schp->page_order = order;
1932         schp->k_use_sg = k;
1933         SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1934                          "sg_build_indirect: k_use_sg=%d, rem_sz=%d\n",
1935                          k, rem_sz));
1936
1937         schp->bufflen = blk_size;
1938         if (rem_sz > 0) /* must have failed */
1939                 return -ENOMEM;
1940         return 0;
1941 out:
1942         for (i = 0; i < k; i++)
1943                 __free_pages(schp->pages[i], order);
1944
1945         if (--order >= 0)
1946                 goto retry;
1947
1948         return -ENOMEM;
1949 }
1950
1951 static void
1952 sg_remove_scat(Sg_fd * sfp, Sg_scatter_hold * schp)
1953 {
1954         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1955                          "sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
1956         if (schp->pages && schp->sglist_len > 0) {
1957                 if (!schp->dio_in_use) {
1958                         int k;
1959
1960                         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1961                                 SCSI_LOG_TIMEOUT(5,
1962                                         sg_printk(KERN_INFO, sfp->parentdp,
1963                                         "sg_remove_scat: k=%d, pg=0x%p\n",
1964                                         k, schp->pages[k]));
1965                                 __free_pages(schp->pages[k], schp->page_order);
1966                         }
1967
1968                         kfree(schp->pages);
1969                 }
1970         }
1971         memset(schp, 0, sizeof (*schp));
1972 }
1973
1974 static int
1975 sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
1976 {
1977         Sg_scatter_hold *schp = &srp->data;
1978         int k, num;
1979
1980         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
1981                          "sg_read_oxfer: num_read_xfer=%d\n",
1982                          num_read_xfer));
1983         if ((!outp) || (num_read_xfer <= 0))
1984                 return 0;
1985
1986         num = 1 << (PAGE_SHIFT + schp->page_order);
1987         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1988                 if (num > num_read_xfer) {
1989                         if (__copy_to_user(outp, page_address(schp->pages[k]),
1990                                            num_read_xfer))
1991                                 return -EFAULT;
1992                         break;
1993                 } else {
1994                         if (__copy_to_user(outp, page_address(schp->pages[k]),
1995                                            num))
1996                                 return -EFAULT;
1997                         num_read_xfer -= num;
1998                         if (num_read_xfer <= 0)
1999                                 break;
2000                         outp += num;
2001                 }
2002         }
2003
2004         return 0;
2005 }
2006
2007 static void
2008 sg_build_reserve(Sg_fd * sfp, int req_size)
2009 {
2010         Sg_scatter_hold *schp = &sfp->reserve;
2011
2012         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
2013                          "sg_build_reserve: req_size=%d\n", req_size));
2014         do {
2015                 if (req_size < PAGE_SIZE)
2016                         req_size = PAGE_SIZE;
2017                 if (0 == sg_build_indirect(schp, sfp, req_size))
2018                         return;
2019                 else
2020                         sg_remove_scat(sfp, schp);
2021                 req_size >>= 1; /* divide by 2 */
2022         } while (req_size > (PAGE_SIZE / 2));
2023 }
2024
2025 static void
2026 sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
2027 {
2028         Sg_scatter_hold *req_schp = &srp->data;
2029         Sg_scatter_hold *rsv_schp = &sfp->reserve;
2030         int k, num, rem;
2031
2032         srp->res_used = 1;
2033         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
2034                          "sg_link_reserve: size=%d\n", size));
2035         rem = size;
2036
2037         num = 1 << (PAGE_SHIFT + rsv_schp->page_order);
2038         for (k = 0; k < rsv_schp->k_use_sg; k++) {
2039                 if (rem <= num) {
2040                         req_schp->k_use_sg = k + 1;
2041                         req_schp->sglist_len = rsv_schp->sglist_len;
2042                         req_schp->pages = rsv_schp->pages;
2043
2044                         req_schp->bufflen = size;
2045                         req_schp->page_order = rsv_schp->page_order;
2046                         break;
2047                 } else
2048                         rem -= num;
2049         }
2050
2051         if (k >= rsv_schp->k_use_sg)
2052                 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
2053                                  "sg_link_reserve: BAD size\n"));
2054 }
2055
2056 static void
2057 sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
2058 {
2059         Sg_scatter_hold *req_schp = &srp->data;
2060
2061         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
2062                                       "sg_unlink_reserve: req->k_use_sg=%d\n",
2063                                       (int) req_schp->k_use_sg));
2064         req_schp->k_use_sg = 0;
2065         req_schp->bufflen = 0;
2066         req_schp->pages = NULL;
2067         req_schp->page_order = 0;
2068         req_schp->sglist_len = 0;
2069         srp->res_used = 0;
2070         /* Called without mutex lock to avoid deadlock */
2071         sfp->res_in_use = 0;
2072 }
2073
2074 static Sg_request *
2075 sg_get_rq_mark(Sg_fd * sfp, int pack_id, bool *busy)
2076 {
2077         Sg_request *resp;
2078         unsigned long iflags;
2079
2080         *busy = false;
2081         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2082         list_for_each_entry(resp, &sfp->rq_list, entry) {
2083                 /* look for requests that are not SG_IO owned */
2084                 if ((!resp->sg_io_owned) &&
2085                     ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
2086                         switch (resp->done) {
2087                         case 0: /* request active */
2088                                 *busy = true;
2089                                 break;
2090                         case 1: /* request done; response ready to return */
2091                                 resp->done = 2; /* guard against other readers */
2092                                 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2093                                 return resp;
2094                         case 2: /* response already being returned */
2095                                 break;
2096                         }
2097                 }
2098         }
2099         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2100         return NULL;
2101 }
2102
2103 /* always adds to end of list */
2104 static Sg_request *
2105 sg_add_request(Sg_fd * sfp)
2106 {
2107         int k;
2108         unsigned long iflags;
2109         Sg_request *rp = sfp->req_arr;
2110
2111         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2112         if (!list_empty(&sfp->rq_list)) {
2113                 if (!sfp->cmd_q)
2114                         goto out_unlock;
2115
2116                 for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2117                         if (!rp->parentfp)
2118                                 break;
2119                 }
2120                 if (k >= SG_MAX_QUEUE)
2121                         goto out_unlock;
2122         }
2123         memset(rp, 0, sizeof (Sg_request));
2124         rp->parentfp = sfp;
2125         rp->header.duration = jiffies_to_msecs(jiffies);
2126         list_add_tail(&rp->entry, &sfp->rq_list);
2127         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2128         return rp;
2129 out_unlock:
2130         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2131         return NULL;
2132 }
2133
2134 /* Return of 1 for found; 0 for not found */
2135 static int
2136 sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2137 {
2138         unsigned long iflags;
2139         int res = 0;
2140
2141         if (!sfp || !srp || list_empty(&sfp->rq_list))
2142                 return res;
2143         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2144         if (!list_empty(&srp->entry)) {
2145                 list_del(&srp->entry);
2146                 srp->parentfp = NULL;
2147                 res = 1;
2148         }
2149         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2150
2151         /*
2152          * If the device is detaching, wakeup any readers in case we just
2153          * removed the last response, which would leave nothing for them to
2154          * return other than -ENODEV.
2155          */
2156         if (unlikely(atomic_read(&sfp->parentdp->detaching)))
2157                 wake_up_interruptible_all(&sfp->read_wait);
2158
2159         return res;
2160 }
2161
2162 static Sg_fd *
2163 sg_add_sfp(Sg_device * sdp)
2164 {
2165         Sg_fd *sfp;
2166         unsigned long iflags;
2167         int bufflen;
2168
2169         sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2170         if (!sfp)
2171                 return ERR_PTR(-ENOMEM);
2172
2173         init_waitqueue_head(&sfp->read_wait);
2174         rwlock_init(&sfp->rq_list_lock);
2175         INIT_LIST_HEAD(&sfp->rq_list);
2176         kref_init(&sfp->f_ref);
2177         mutex_init(&sfp->f_mutex);
2178         sfp->timeout = SG_DEFAULT_TIMEOUT;
2179         sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2180         sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2181         sfp->cmd_q = SG_DEF_COMMAND_Q;
2182         sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2183         sfp->parentdp = sdp;
2184         write_lock_irqsave(&sdp->sfd_lock, iflags);
2185         if (atomic_read(&sdp->detaching)) {
2186                 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2187                 kfree(sfp);
2188                 return ERR_PTR(-ENODEV);
2189         }
2190         list_add_tail(&sfp->sfd_siblings, &sdp->sfds);
2191         write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2192         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2193                                       "sg_add_sfp: sfp=0x%p\n", sfp));
2194         if (unlikely(sg_big_buff != def_reserved_size))
2195                 sg_big_buff = def_reserved_size;
2196
2197         bufflen = min_t(int, sg_big_buff,
2198                         max_sectors_bytes(sdp->device->request_queue));
2199         sg_build_reserve(sfp, bufflen);
2200         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2201                                       "sg_add_sfp: bufflen=%d, k_use_sg=%d\n",
2202                                       sfp->reserve.bufflen,
2203                                       sfp->reserve.k_use_sg));
2204
2205         kref_get(&sdp->d_ref);
2206         __module_get(THIS_MODULE);
2207         return sfp;
2208 }
2209
2210 static void
2211 sg_remove_sfp_usercontext(struct work_struct *work)
2212 {
2213         struct sg_fd *sfp = container_of(work, struct sg_fd, ew.work);
2214         struct sg_device *sdp = sfp->parentdp;
2215         Sg_request *srp;
2216         unsigned long iflags;
2217
2218         /* Cleanup any responses which were never read(). */
2219         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2220         while (!list_empty(&sfp->rq_list)) {
2221                 srp = list_first_entry(&sfp->rq_list, Sg_request, entry);
2222                 sg_finish_rem_req(srp);
2223                 list_del(&srp->entry);
2224                 srp->parentfp = NULL;
2225         }
2226         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2227
2228         if (sfp->reserve.bufflen > 0) {
2229                 SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2230                                 "sg_remove_sfp:    bufflen=%d, k_use_sg=%d\n",
2231                                 (int) sfp->reserve.bufflen,
2232                                 (int) sfp->reserve.k_use_sg));
2233                 sg_remove_scat(sfp, &sfp->reserve);
2234         }
2235
2236         SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2237                         "sg_remove_sfp: sfp=0x%p\n", sfp));
2238         kfree(sfp);
2239
2240         scsi_device_put(sdp->device);
2241         kref_put(&sdp->d_ref, sg_device_destroy);
2242         module_put(THIS_MODULE);
2243 }
2244
2245 static void
2246 sg_remove_sfp(struct kref *kref)
2247 {
2248         struct sg_fd *sfp = container_of(kref, struct sg_fd, f_ref);
2249         struct sg_device *sdp = sfp->parentdp;
2250         unsigned long iflags;
2251
2252         write_lock_irqsave(&sdp->sfd_lock, iflags);
2253         list_del(&sfp->sfd_siblings);
2254         write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2255
2256         INIT_WORK(&sfp->ew.work, sg_remove_sfp_usercontext);
2257         schedule_work(&sfp->ew.work);
2258 }
2259
2260 #ifdef CONFIG_SCSI_PROC_FS
2261 static int
2262 sg_idr_max_id(int id, void *p, void *data)
2263 {
2264         int *k = data;
2265
2266         if (*k < id)
2267                 *k = id;
2268
2269         return 0;
2270 }
2271
2272 static int
2273 sg_last_dev(void)
2274 {
2275         int k = -1;
2276         unsigned long iflags;
2277
2278         read_lock_irqsave(&sg_index_lock, iflags);
2279         idr_for_each(&sg_index_idr, sg_idr_max_id, &k);
2280         read_unlock_irqrestore(&sg_index_lock, iflags);
2281         return k + 1;           /* origin 1 */
2282 }
2283 #endif
2284
2285 /* must be called with sg_index_lock held */
2286 static Sg_device *sg_lookup_dev(int dev)
2287 {
2288         return idr_find(&sg_index_idr, dev);
2289 }
2290
2291 static Sg_device *
2292 sg_get_dev(int dev)
2293 {
2294         struct sg_device *sdp;
2295         unsigned long flags;
2296
2297         read_lock_irqsave(&sg_index_lock, flags);
2298         sdp = sg_lookup_dev(dev);
2299         if (!sdp)
2300                 sdp = ERR_PTR(-ENXIO);
2301         else if (atomic_read(&sdp->detaching)) {
2302                 /* If sdp->detaching, then the refcount may already be 0, in
2303                  * which case it would be a bug to do kref_get().
2304                  */
2305                 sdp = ERR_PTR(-ENODEV);
2306         } else
2307                 kref_get(&sdp->d_ref);
2308         read_unlock_irqrestore(&sg_index_lock, flags);
2309
2310         return sdp;
2311 }
2312
2313 #ifdef CONFIG_SCSI_PROC_FS
2314 static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2315
2316 static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2317 static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2318                                   size_t count, loff_t *off);
2319 static const struct file_operations adio_fops = {
2320         .owner = THIS_MODULE,
2321         .open = sg_proc_single_open_adio,
2322         .read = seq_read,
2323         .llseek = seq_lseek,
2324         .write = sg_proc_write_adio,
2325         .release = single_release,
2326 };
2327
2328 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2329 static ssize_t sg_proc_write_dressz(struct file *filp,
2330                 const char __user *buffer, size_t count, loff_t *off);
2331 static const struct file_operations dressz_fops = {
2332         .owner = THIS_MODULE,
2333         .open = sg_proc_single_open_dressz,
2334         .read = seq_read,
2335         .llseek = seq_lseek,
2336         .write = sg_proc_write_dressz,
2337         .release = single_release,
2338 };
2339
2340 static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2341 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2342 static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2343 static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2344 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2345 static void dev_seq_stop(struct seq_file *s, void *v);
2346 static const struct seq_operations dev_seq_ops = {
2347         .start = dev_seq_start,
2348         .next  = dev_seq_next,
2349         .stop  = dev_seq_stop,
2350         .show  = sg_proc_seq_show_dev,
2351 };
2352
2353 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2354 static const struct seq_operations devstrs_seq_ops = {
2355         .start = dev_seq_start,
2356         .next  = dev_seq_next,
2357         .stop  = dev_seq_stop,
2358         .show  = sg_proc_seq_show_devstrs,
2359 };
2360
2361 static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2362 static const struct seq_operations debug_seq_ops = {
2363         .start = dev_seq_start,
2364         .next  = dev_seq_next,
2365         .stop  = dev_seq_stop,
2366         .show  = sg_proc_seq_show_debug,
2367 };
2368
2369 static int
2370 sg_proc_init(void)
2371 {
2372         struct proc_dir_entry *p;
2373
2374         p = proc_mkdir("scsi/sg", NULL);
2375         if (!p)
2376                 return 1;
2377
2378         proc_create("allow_dio", S_IRUGO | S_IWUSR, p, &adio_fops);
2379         proc_create_seq("debug", S_IRUGO, p, &debug_seq_ops);
2380         proc_create("def_reserved_size", S_IRUGO | S_IWUSR, p, &dressz_fops);
2381         proc_create_single("device_hdr", S_IRUGO, p, sg_proc_seq_show_devhdr);
2382         proc_create_seq("devices", S_IRUGO, p, &dev_seq_ops);
2383         proc_create_seq("device_strs", S_IRUGO, p, &devstrs_seq_ops);
2384         proc_create_single("version", S_IRUGO, p, sg_proc_seq_show_version);
2385         return 0;
2386 }
2387
2388
2389 static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2390 {
2391         seq_printf(s, "%d\n", *((int *)s->private));
2392         return 0;
2393 }
2394
2395 static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2396 {
2397         return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2398 }
2399
2400 static ssize_t
2401 sg_proc_write_adio(struct file *filp, const char __user *buffer,
2402                    size_t count, loff_t *off)
2403 {
2404         int err;
2405         unsigned long num;
2406
2407         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2408                 return -EACCES;
2409         err = kstrtoul_from_user(buffer, count, 0, &num);
2410         if (err)
2411                 return err;
2412         sg_allow_dio = num ? 1 : 0;
2413         return count;
2414 }
2415
2416 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2417 {
2418         return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2419 }
2420
2421 static ssize_t
2422 sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2423                      size_t count, loff_t *off)
2424 {
2425         int err;
2426         unsigned long k = ULONG_MAX;
2427
2428         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2429                 return -EACCES;
2430
2431         err = kstrtoul_from_user(buffer, count, 0, &k);
2432         if (err)
2433                 return err;
2434         if (k <= 1048576) {     /* limit "big buff" to 1 MB */
2435                 sg_big_buff = k;
2436                 return count;
2437         }
2438         return -ERANGE;
2439 }
2440
2441 static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2442 {
2443         seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2444                    sg_version_date);
2445         return 0;
2446 }
2447
2448 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2449 {
2450         seq_puts(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\tonline\n");
2451         return 0;
2452 }
2453
2454 struct sg_proc_deviter {
2455         loff_t  index;
2456         size_t  max;
2457 };
2458
2459 static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2460 {
2461         struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2462
2463         s->private = it;
2464         if (! it)
2465                 return NULL;
2466
2467         it->index = *pos;
2468         it->max = sg_last_dev();
2469         if (it->index >= it->max)
2470                 return NULL;
2471         return it;
2472 }
2473
2474 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2475 {
2476         struct sg_proc_deviter * it = s->private;
2477
2478         *pos = ++it->index;
2479         return (it->index < it->max) ? it : NULL;
2480 }
2481
2482 static void dev_seq_stop(struct seq_file *s, void *v)
2483 {
2484         kfree(s->private);
2485 }
2486
2487 static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2488 {
2489         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2490         Sg_device *sdp;
2491         struct scsi_device *scsidp;
2492         unsigned long iflags;
2493
2494         read_lock_irqsave(&sg_index_lock, iflags);
2495         sdp = it ? sg_lookup_dev(it->index) : NULL;
2496         if ((NULL == sdp) || (NULL == sdp->device) ||
2497             (atomic_read(&sdp->detaching)))
2498                 seq_puts(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2499         else {
2500                 scsidp = sdp->device;
2501                 seq_printf(s, "%d\t%d\t%d\t%llu\t%d\t%d\t%d\t%d\t%d\n",
2502                               scsidp->host->host_no, scsidp->channel,
2503                               scsidp->id, scsidp->lun, (int) scsidp->type,
2504                               1,
2505                               (int) scsidp->queue_depth,
2506                               (int) atomic_read(&scsidp->device_busy),
2507                               (int) scsi_device_online(scsidp));
2508         }
2509         read_unlock_irqrestore(&sg_index_lock, iflags);
2510         return 0;
2511 }
2512
2513 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2514 {
2515         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2516         Sg_device *sdp;
2517         struct scsi_device *scsidp;
2518         unsigned long iflags;
2519
2520         read_lock_irqsave(&sg_index_lock, iflags);
2521         sdp = it ? sg_lookup_dev(it->index) : NULL;
2522         scsidp = sdp ? sdp->device : NULL;
2523         if (sdp && scsidp && (!atomic_read(&sdp->detaching)))
2524                 seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2525                            scsidp->vendor, scsidp->model, scsidp->rev);
2526         else
2527                 seq_puts(s, "<no active device>\n");
2528         read_unlock_irqrestore(&sg_index_lock, iflags);
2529         return 0;
2530 }
2531
2532 /* must be called while holding sg_index_lock */
2533 static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2534 {
2535         int k, new_interface, blen, usg;
2536         Sg_request *srp;
2537         Sg_fd *fp;
2538         const sg_io_hdr_t *hp;
2539         const char * cp;
2540         unsigned int ms;
2541
2542         k = 0;
2543         list_for_each_entry(fp, &sdp->sfds, sfd_siblings) {
2544                 k++;
2545                 read_lock(&fp->rq_list_lock); /* irqs already disabled */
2546                 seq_printf(s, "   FD(%d): timeout=%dms bufflen=%d "
2547                            "(res)sgat=%d low_dma=%d\n", k,
2548                            jiffies_to_msecs(fp->timeout),
2549                            fp->reserve.bufflen,
2550                            (int) fp->reserve.k_use_sg,
2551                            (int) sdp->device->host->unchecked_isa_dma);
2552                 seq_printf(s, "   cmd_q=%d f_packid=%d k_orphan=%d closed=0\n",
2553                            (int) fp->cmd_q, (int) fp->force_packid,
2554                            (int) fp->keep_orphan);
2555                 list_for_each_entry(srp, &fp->rq_list, entry) {
2556                         hp = &srp->header;
2557                         new_interface = (hp->interface_id == '\0') ? 0 : 1;
2558                         if (srp->res_used) {
2559                                 if (new_interface &&
2560                                     (SG_FLAG_MMAP_IO & hp->flags))
2561                                         cp = "     mmap>> ";
2562                                 else
2563                                         cp = "     rb>> ";
2564                         } else {
2565                                 if (SG_INFO_DIRECT_IO_MASK & hp->info)
2566                                         cp = "     dio>> ";
2567                                 else
2568                                         cp = "     ";
2569                         }
2570                         seq_puts(s, cp);
2571                         blen = srp->data.bufflen;
2572                         usg = srp->data.k_use_sg;
2573                         seq_puts(s, srp->done ?
2574                                  ((1 == srp->done) ?  "rcv:" : "fin:")
2575                                   : "act:");
2576                         seq_printf(s, " id=%d blen=%d",
2577                                    srp->header.pack_id, blen);
2578                         if (srp->done)
2579                                 seq_printf(s, " dur=%d", hp->duration);
2580                         else {
2581                                 ms = jiffies_to_msecs(jiffies);
2582                                 seq_printf(s, " t_o/elap=%d/%d",
2583                                         (new_interface ? hp->timeout :
2584                                                   jiffies_to_msecs(fp->timeout)),
2585                                         (ms > hp->duration ? ms - hp->duration : 0));
2586                         }
2587                         seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2588                                    (int) srp->data.cmd_opcode);
2589                 }
2590                 if (list_empty(&fp->rq_list))
2591                         seq_puts(s, "     No requests active\n");
2592                 read_unlock(&fp->rq_list_lock);
2593         }
2594 }
2595
2596 static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2597 {
2598         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2599         Sg_device *sdp;
2600         unsigned long iflags;
2601
2602         if (it && (0 == it->index))
2603                 seq_printf(s, "max_active_device=%d  def_reserved_size=%d\n",
2604                            (int)it->max, sg_big_buff);
2605
2606         read_lock_irqsave(&sg_index_lock, iflags);
2607         sdp = it ? sg_lookup_dev(it->index) : NULL;
2608         if (NULL == sdp)
2609                 goto skip;
2610         read_lock(&sdp->sfd_lock);
2611         if (!list_empty(&sdp->sfds)) {
2612                 seq_printf(s, " >>> device=%s ", sdp->disk->disk_name);
2613                 if (atomic_read(&sdp->detaching))
2614                         seq_puts(s, "detaching pending close ");
2615                 else if (sdp->device) {
2616                         struct scsi_device *scsidp = sdp->device;
2617
2618                         seq_printf(s, "%d:%d:%d:%llu   em=%d",
2619                                    scsidp->host->host_no,
2620                                    scsidp->channel, scsidp->id,
2621                                    scsidp->lun,
2622                                    scsidp->host->hostt->emulated);
2623                 }
2624                 seq_printf(s, " sg_tablesize=%d excl=%d open_cnt=%d\n",
2625                            sdp->sg_tablesize, sdp->exclude, sdp->open_cnt);
2626                 sg_proc_debug_helper(s, sdp);
2627         }
2628         read_unlock(&sdp->sfd_lock);
2629 skip:
2630         read_unlock_irqrestore(&sg_index_lock, iflags);
2631         return 0;
2632 }
2633
2634 #endif                          /* CONFIG_SCSI_PROC_FS */
2635
2636 module_init(init_sg);
2637 module_exit(exit_sg);